<template>
  <div class="nav-bar" :class="{'is_fixed':isFixed}">
    <div class="container">
      <div class="pro-title">{{title}}</div>
      <div class="pro-param">
        <a href="javascript:;">概述</a><span>|</span>
        <a href="javascript:;">参数</a><span>|</span>
        <a href="javascript:;">用户评价</a>
        <slot name="buy"></slot>
      </div>
    </div>
  </div>
</template>

<script>
  export default {
    name: "ProductParam",
    data() {
      return {
        isFixed: false
      }
    },
    props: {
      title: String
    },
    mounted() {
      window.addEventListener('scroll', this.initHeight);
    },
    methods: {
      initHeight() {
        let scrollTop = window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop;
        this.isFixed = scrollTop > 152 ? true : false;
      }
    },
    destroyed() {
      window.removeEventListener('scroll', this.initHeight, false);
    }
  }
</script>

<style lang="scss" scoped>

  @import "../assets/scss/config";
  @import "../assets/scss/mixin";

  .nav-bar {
    height: 70px;
    line-height: 70px;
    border-top: 1px solid $colorH;
    background-color: $colorG;

    &.is_fixed {
      position: fixed;
      top: 0;
      z-index: 12;
      width: 100%;
      box-shadow: 0 5px 5px $colorE;
    }

    .container {
      @include flex();
    }

    .pro-title {
      font-size: $fontH;
      color: $colorB;
      font-weight: bold;
    }

    .pro-param {
      font-size: $fontJ;

      a {
        color: $colorC;
      }

      span {
        margin: 0 10px;
      }
    }
  }
</style>
